This invention relates to a device for use in a well for connecting the ground wire from a submersible well pump to the well casing.
In a well system, it is desirable to connect the well pump to the ground of the main electrical system. In many states, grounding of the well pump is required by the state electrical code. In Wisconsin, for example, the state electrical code specifies that the motor frame of the submersible well pump must be grounded by an equipment grounding conductor, which must be bonded to the metallic well casing.
One system for bonding the ground wire to the well casing involves drilling a hole in the well casing toward its upper end and tapping the hole. A grounding stud is then threaded into the tapped hole, and is used to establish a grounding connection between the well casing and the ground wire. A disadvantage to this system is that the procedure for drilling and tapping the hole into the well casing is carried out after the casing is installed, making the enumerated steps somewhat difficult to carry out. Additionally, piercing the well casing adversely affects the overall integrity of the casing. Further, sanitary problems can result from drilling a hole into a well casing due to outside water and other fluids entering the casing through the hole.
The present invention has as its object to provide an assembly for establishing a ground connection between the well casing and a ground wire without the need for drilling and tapping a hole in the well casing. Another object of the invention is to provide a system for establishing a ground connection which is simple in construction and easily installed at the upper end of the well casing, and which can be removed from the well casing.
In accordance with the invention, an assembly for connecting a ground wire to a well casing generally comprises a removable support member for placement into the casing toward its upper end, and means for fixing the position of the support member relative to the well casing. Ground connection means is engagable with the support member for establishing a grounding connection between the ground wire and the interior of the well casing without connection to the exterior of the well casing. The dimensions of the support member are in all respects less than the internal transverse dimension of the well casing, for allowing placement of the support member into the interior of the well casing. The support member is preferably provided with a pair of opposed suspension members, each of which includes a lateral tab, with the tabs being adapted to rest on top of the well casing for suspending the support member within the well casing.
In one embodiment, the support member extends radially between the suspension members. A threaded member extending through a threaded opening in one of the suspension members, and engagable with an interior surface of the well casing to secure the support member to the well casing. The threaded member also establishes a ground connection between the support member and the well casing. A threaded stud or the like is mounted to the other of the suspension members. A nut is engagable with the threaded stud, for connecting the ground wire to the threaded stud and establishing a ground connection to the well casing through the support member and the suspension members.
In another embodiment, the support member comprises a ring adapted for placement into the well casing, from which the suspension members extend upwardly. The suspension members and tabs fix the vertical position of the support ring relative to the well casing, while allowing lateral movement of the support ring. The ground wire is positioned between a surface of the support ring and an interior surface of the well casing, and lateral movement of the support member is caused by wedging means which bears between an interior surface of the well casing and a surface of the support ring substantially opposite the location of the grounding wire. The wedging means is operable to cause lateral movement of the support ring toward the well casing, to wedge the grounding wire between the support ring and the well casing and to establish a grounding connection of the ground wire to the well casing. The wedging means preferably comprises a screw engagable with a threaded opening formed in the support ring. Turning down the screw results in its end engaging the wall of the casing, causing movement of the support ring toward the ground wire.
In yet another embodiment, the support member comprises a ring, from which the suspension members extend upwardly. A series of openings are formed in the ring, and self-tapping screws or the like extend through the openings and bear at their ends against the interior surface of the well casing for fixing the position of the ring. A set screw extends through a threaded opening in the ring, and its inner end engages the grounding wire to force it against the inner surface of the well casing to establish a ground connection.